Several different disciplines have been pushing the envelope for user experiences wherein a user is immersed in an environment with virtual sensations for vision, hearing, and touch. In the area of vision, current technology for 3-D displays continues to improve. Three-dimensional (“3-D”) display technologies may include, but are not limited to, stereoscopic, autosterescopic, anaglyph, lenticular, lenslet, barrier line, coded aperture, micropolarizer, view sequential, volumetric (including free-space and swept volume displays), waveguide directional, panoramagram, frustrated total internal reflection, liquid lens, backlight steering/eye-tracked, coupled electro-optic, flying fiber, nanophotonic array, nanoantenna tuned laser, and holographic images. In the area of hearing, directed audio technology makes it so that a sound is audible in only a limited volume in space, while the sound may be completely inaudible in an adjacent volume in space. Other audio technologies include parametric speakers, “holosonic” audio, “hypersonic” audio, audio demodulation, nonlinear difference frequency generation and multi-wave mixing. In the area of touch, ultrasonic tactile fields is a rapidly developing technology by which specially placed sound energy, frequently generated by ultrasonic transducers, allows a person to feel the sound waves as virtual shapes in space even though the space is void of physical objects.
Current development of these technologies includes efforts to combine two of these three senses (i.e., visual, audio, and tactile) in the same experience, e.g., visual and tactile, or visual and audio. For example, combining visual and tactile sensations in the same experience could result in a person seeing an object represented as a 3-D hologram and being able to feel, via a tactile field, that object. Combining visual and audio sensations in the same experience could result in a person seeing an object represented as a 3-D hologram and hearing sounds that appear to originate from the object, and even from different parts of the object.
Several proposals for generating a multi-sense effect, i.e., combining visual, audio, and tactile, or a two-sense combination from these three senses, have been suggested, but suffer from significant shortcomings. In one approach, shown in FIG. 1, a planar device 110 for generating a 3-D display 150 from optical wavefront 160 is orthogonal relative to a plane 120 having ultrasonic transducers 130a . . . n for generating a tactile field 150 from acoustic wavefront 170. Note that item 150 represents both a 3-D display and a tactile field.
Previous approaches have also relied on headphones for sound in conjunction with a 3-D display, but headphones are an encumbrance to the freedom of experiencing a 3-D field. Other previous approaches have suggested the use of parametric (directional) speakers located orthogonal relative to a 3-D display
Although approaches involving ultrasonic transducers or parametric speakers orthogonally disposed relative to a 3-D display may suffice for applications requiring only one unit, i.e., one 3-D display plane with one plane having ultrasonic transducers or parametric speakers, such approaches are not scalable. For example, to generate a large 3-D display with directed sound and a tactile field, two options are available. The first, as shown in FIG. 2, is to generate a very large 3-D display 210 located orthogonally to an equally large plane 220 for ultrasonic transducers or parametric speakers 230a . . . n. This first option has the undesirable side effect of requiring a large plane on which a user 240 may be required to stand to interact with the multi-sense experience 250, or may require taking up an entire wall for one of the orthogonal planar surfaces. In addition to the potential for damage resulting from user 240 standing on planar surface 220, the large distances from the furthest extents of 3-D display plane 210 to the furthest extents of plane 220 containing ultrasonic transducers or parametric speakers may make it difficult to present all sensations (sight and one or both of sound and tactile) at some locations.
A second option, as shown in FIG. 3, is to tile units 310a . . . n, each comprising a 3-D display plane 311n and plane 312n with ultrasonic transducers or parametric speakers orthogonally disposed relative each other. This option is undesirable because orthogonally disposed planes 312a . . . n protrude from the wall of tiled units 311a . . . n, and also because protruding planes 312a . . . 312n will interfere with the 3-D display functionality, tactile field, and directed audio functionality from other units. For example, light 360 from 3-D display plane 350 is blocked by orthogonally disposed plane 370.
What is needed is a tileable and scalable unit capable of generating a 3-D display with directed audio and/or a tactile field.